Devices for the tuning of stringed instruments



Feb. 24, 1970 wfls'rl. 3,496,825

DEVICES FOR THE TUNING OF STRING INSTRUMENTS Filed Jan. 23, 1967 3Sheets-Sheet l (mum ' I LvNEwTo has \nliisrp T1- 0 RaGY 5 Feb. 24, 1970I H. WUSTL 3,495,825

DEVICES FOR THE TUNING OF STRING INSTRUMENTS Fi led Jan. 23, 1967 3Sheets-Sheet 2 18h! ERTo H. wUs-n.

FeB. 24, 1970 1 DEVICES FOR THE TUNING OF STRING INSTRUMENTS Filed Jan.23, 1967 3 Sheets-Sheet 3 ALI TQ W W WWNQ I I R Q United States PatentOffice 3,496,825 Patented Feb. 24, 1970 3,496,825 DEVICES FOR THE TUNINGF STRINGED INSTRUMENTS Hans Wiistl, Waldstrasse 41, Bubenreuth, nearErlangen, Germany Filed Jan. 23, 1967, Ser. No. 610,892 Claims priority,application Germany, Jan. 26, 1966,

Int. Cl. Gd 3/14 US. Cl. 84306 6 Claims ABSTRACT OF THE DISCLOSURE Atuning device for a stringed musical instrument with which a selectedone of the strings of the instrument can be gradually and accuratelytuned by continually biasing a spindle into rotation transmittingplay-free engagement with a worm wheel which, in turn, is secured to arotary shaft having secured thereto the string to be tuned.

The present invention relates to a device for the tuning of stringinstruments (a so-called mechanics) comprising a worm gear which hasbeen located on a plate its wheel being supported on a shaft serving forwinding up the string and its spindle one end of which has been providedwith a turning handle being supported on either side of its threadedportion.

With devices of the present type rapid, free from play engagement ofspindle and wheel will be required in order to ensure quick, secure andaccurate tuning of the strings pitch.

In the devices already known spindle and wheel of the worm gear arelocated on a plate which will be screwed onto the string instrument,while the bearing shaft of the wheel is located in a bore of the plateand the spindle is supported by two brackets fixed to the plate. In thisconnection it is already known to provide the plate in such a mannerthat it is at the same time bearing the spindle. For this purpose, forinstance, on either side of the plate vertical projections with bores toreceive the spindle have been provided, or the spindle bearings togetherwith the plate have been produced from one piece, for instance, by sprayor pressure casting.

In these devices already known the distance between spindle and wheelaxles is always the same. Consequently, free from play engagementbetween spindle and wheel will not be guaranteed unless the individualcomponents of the device will have been produced and assembled observingutmost precision in which case observation or" the appropriate axledistance will be most decisive. However, in the production of thesedevices application of maximum accuracy is undesirable with respect tocosts, resulting in the fact widely known, i.e. that the devices on themarket are subject to considerable play. If the distance between spindleand wheel axles is smaller than the theoretical toothing value, thewormgear will be subjectto obstruction. If the distance between axles isgreater than said theoretical toothing value, there will be play betweenthe tooth profile of spindle and wheel.

If, for instance, the string is tuned to a higher pitch, the toothprofile of the spindle will contact without any play the tooth profileof the wheel which is submitted to the tensional force of the string.If, however, the string is subsequently tuned to a lower pitch, i.e. ifthe spindle is turned into the opposite direction, the wheel is noteasily following the spindle movement, but it is following the same moreor less with jerks until the existing play will have been overcome andfree from play engagement between spindle and wheel restored. Precisetuning of the string will usually be eifected by repeated higher andlower tuning around the desired tone until the player of the stringinstrument will gradually have arrived at said desired tone. Butespecially in this case such play will be extremely annoying. For inextreme cases, i.e. if the desired tone is exactly located in the gapdefined by the play between wheel and worm, precise tuning will not bepossible at all.

Such unfavorable effect as described does, however, not only occur inthe presence of excess distance between axles. Any play between spindleand wheel profiles resulting from inaccurate toothing as well as anyplay in the spindle or wheel bearings will have the same unfavorableeffect. It may even happen that play occurs in a gear which hasinitially been free from play after prolonged utilisation of the stringinstrument due to wear.

Play will be especially great in those cases where several individualplays are acting in the same direction. On the other hand, it may alsohappen of course that several individual plays acting in oppositedirections may partly or completely neutralise their total effect thussimulating more or less play free engagement of spindle and wheel.

The object of the present invention is to abolish the unfavorableinfiuence of various individual plays in the devices for the tuning ofstring instruments and to guarantee rapid, secure and accurate tuning ofthe string.

This problem has been solved in that the spindle has been supported onthe plate so that it may move in the direction towards the wheel and/orthe wheel has been supported on the plate so that it may move in thedirection towards the spindle, and in that they are subject to adirective force acting with respect to the wheel and/or the spindlerespectively.

According to the present invention there have been provided, if thedirective force is acting on the spindle. movable brackets on the platefor supporting the spindle and strips for guiding said brackets.According to the present invention the directive force is at least sogreat as or greater than the radial force of the worm gear. Preferably,the value of the directive force is not constant. The force may beproduced by the pressure against the spindle exerted by adjustingadjusting screws or springs, such as compressions springs, which havebeen provided on the plate and which, in a preferred embodiment of thepresent invention, are supported against adjusting screws which areprovided on the plate said springs acting on the brackets in thedirection towards the wheel.

Further embodiments according to the present invention are characterisedin that the plate is a bending spring with hearings to support thespindle in which case the spindle bearings are flaps of the bendingspring which are rolled inwards in the form of claws. The bending springmay contact the outside of the wheel by means of a partial area whilepressing the same against the neck of the string instrument.

In another embodiment according to the present invention the plate maybe rigid. In this case there has been provided, according to theinvention, a bending spring in the form of a clip one end of which isfixed to the plate while the other end is gripping from behind themovably supported spindle. This arrangement will be favorable in thatthe plate may be designed in a particularly solid construction. Inaddition, it will also be favorable that the bending spring is pressingthe gear wheel against the plate if it is placed, according to anotherfeature of the present invention, over a wheel projection. by means of alongitudinal slot and is contacting the wheel under axial pressure.

According to the present invention, therefore, the bending spring isresponsible both for pressing the spindle against the gear wheel and forpressing the gear. wheel against the supporting plate.

Preferably, a construction according to the present invention providesfor the feature that one end of the bending spring is gripping behind anose in the form of a hook said nose being attached to the plate at acertain distance from the same, while the spindle may movably besupported in longitudinal slots of lateral faces which have been fixedto the plate at an angle.

Further features, details and advantages of the present invention may beseen from the following description of some preferred examples ofconstructions according to the present invention as well as from theaccompanying drawing in which:

FIG. 1 is a lateral view of an example of a construction according tothe present invention;

FIG. 2 is a bottom view;

FIG. 3 is a bottom view of a second embodiment according to the presentinvention;

FIG. 4 is a lateral view of a third example the section being drawnalong the line IVIV in FIG. 5;

FIG. 5 is a bottom view of this embodiment;

FIG. 6 is a fourth embodiment showing a lateral view;

FIG. 7 is another example of a construction according to the presentinvention showing a lateral view in which the neck of the instrument hasbeen omitted; and

FIG. 8 is a bottom view of FIG. 7.

In FIGS. 1 and 2 the plate 2 has been fixed by means of the two screws 3and 3' to the neck 1 of the string instrument, for instance, of aguitar. The worm or wheel 4 and the spindle 5 of the worm gear aresupported on said plate 2. The wheel 4 is held by means of the shaft 6which is contacting the plate 2 from above by means of the step holder7, and by means of the screw 8. The shaft 6 is provided with a hole 9 atits upper end to receive the string 10. The shaft ends of the spindle 5are supported in the two brackets or bearings 11 and 11' on either sideof the worm part which brackets are movable on the plate. Guidance ofsaid brackets in the lateral directions is effected by the angular flaps12 and 12 on either side at the plate edge. 'Iwo compression springs 13and 13' are acting upon the brackets 11 and 11' the other ends of saidsprings being supported against the adjusting screws 14 and 14'. Saidadjusting screws are adjustable in a flange 15 of the plate 2. Thespindle 4 is activated by means of the turning handle 16.-

FIG. 3 is an example of a construction according to the presentinvention in which the directive force acting on the spindle 5 isproduced by a tension spring 19. As is the case in FIGS. 1 and 2, thewheel 4 is supported on a plate 25. The spindle 5 is supported in thebranches 17 and 17' of the support 18 which is like a bow and is subjectto the effect of the tension spring 19 the eyes of which are fixed tothe support at 20 on one side and to the plate at 21 on the other side,in the presence of prestress.

In FIGS. 4 and 5 the plate is a bending on leaf spring 26 and has forthis end been provided on one end with two claw like supports 22 and 22"to receive the spindle ends 23 and 23'.

FIG. 6 also shows a device with a plate which is a bending spring 27which has, however, been bent towards the outside and the claws 28 and28' of which are gripping the spindle ends 23 and 23' from thebottomside. The bending spring 27 presses the wheel 4 against the socket24 inserted into the neck 1 of the guitar.

In the embodiments of the present invention as shown in FIGS. 7 and 8the wheel 4 is supported by the plate 29 by means of the shaft 6 and thespindle 5 is journaled in two lateral flanges 30 and 30' of the plate bymeans of its ends 23 and 23', said lateral flanges being fixed to theplate 29 at an angle, preferably by bending so that they are one piecetogether with said plate.

The shaft 6 is lengthwise retained with reference to the plate 29 bymeans of its step or shoulder 33 which support is effected by a leafspring 35 which is bent to act as a clip and which, by means of itselongate slot 32, engages the pin projection 31 of the wheel 4.

Said spring 35 is gripping from behind a nose 37 by 4 means of itshooked end 36, said nose being located at the flange 34 of the plate 29.

By means of its other end 38 which is like a claw and rolled inwards,the spring 35 grips the spindle 5, preferably at the threaded portion ofthe same. Consequently, the spring 35 exerts a directive force on thespindle 5 in the direction towards the wheel 4.

As stated before, the shaft ends 23 and 23' of the spindle 5 aresupported in the lateral flanges 30 and 30 of the plate 29. To this end,said lateral flanges have each a longitudinal slot 39 and 39'respectively in which the spindle 5 may move in the direction towardsthe wheel 4 and back.

It is advantageous to make the wheel 4 and the shaft 6, as is the casein the embodiment shown, as an integral part.

As may be seen from the drawing, the embodiment shown is especiallyfavorable with respect to its production and its assembly is verysimple.

Due to pressing of the spindle against the wheel by means of a directiveforce a rapid play free engagement between the spindle and the wheel isobtained according to the present invention enabling, therefore, quickand accurate tuning of the instrument strings. As compared to thedevices already known the device for the tuning of the strings of,musical instruments has further important favorable features. For thefirst a distance between axles which is too small, which with thedevices already known providing for rigid spindle bearing results inblacking, is compensated by the spring support of the spindle; secondly,from the same reason, automatic adjustment of the spindle in the case ofwear of the wheel and/ or the spindle is effected.

As has already been mentioned, the idea of the present invention mayalso be realised in that the directive force is acting against the wheelin the direction towards the spindle in which case, for instance, theshaft 6 may at least be movable in the plate 2. If so desired, the ideaof the present invention may also be realised in that a directive forceis acting on the spindle against the wheel and a directive borce on thewheel against the spindle.

I claim:

1. A device for tuning strings of a stringed musical instrument having aneck portion, said device comprising in combination:

a support plate attachable to the neck portion of the instrument;

a shaft rotatably supported by said plate protruding at both endstherefrom, one protruding end of the shaft being arranged to securethereto one end of a string to be tuned;

a worm gear means including a worm wheel and a coacting spindle, saidworm wheel being secured to the other protruding end of the shaft forrotating the shaft by rotation of the worm wheel;

mounting means on the support plate rotatably sup porting the spindleand displaceable parallel to its axis and normal to the rotational axisof the worm wheel; and

bias means included in said mounting means and directionally biasingsaid spindle into continuous rotation transmitting engagement with saidWorm whel, said bias means including a springy portion on said mountingmeans, said springy portion defining a bearing rotatably supporting thespindle and biasing the same into said continuous play-free engagementwith the worm wheel,

whereby rotation of' said spindle in either direction and correspondingrotation of the shaft causes a corresponding play-free tightening orslackening of a string secured to the shaft.

2. The device according to claim 1 wherein the bias means included insaid mounting means comprises a leaf spring connected on one end to saidsupport plate, the free end of the leaf spring biasing the spindle intosaid continuous play-free engagement with the worm wheel.

3. The device according to claim 2 wherein said one end of the leafspring terminates in a hook portion releasably engaged with a noseportion on the support plate.

4. The device according to claim 2 wherein said support plate hasthereon a pair of parallel flanges extending normal to the rotationalaxis of the worm Wheel, each of said flanges including a lengthwiseelongate slot, said spindle being rotatably held in said slotsdisplaceable therein parallel to its axis, said free end of the leafspring biasing the spindle into said rotation transmitting playfreeengagement with the worm wheel.

5. The device according to claim 2 wherein said leaf 5 for securing thestring thereto and said worm wheel are made of one piece.

References Cited UNITED STATES PATENTS 1/1885 Hyde 84306 9/1874 White84-306 RICHARD B. WILKINSON, Primary Examiner spring includes anelongate opening engaged by a pro- 15 L. R. FRANKLIN, Assistant Examiner

